This disclosure relates to video cameras in general and, in particular, to video cameras having optical zoom capability.
In cameras that have optics that provide variable zoom capability, it is generally found that when a camera is zoomed in on a target object that has been centered in the center of the frame, the target object is off-center from the original center. The more the camera is zoomed in, the more the object is off-center. In handheld cameras the effect is less noticeable since the user manually corrects to keep the desired center of the image centered in the viewfinder of the camera. However, it is annoying at the very least and may be challenging for the user to adjust the camera such that the object can be centered when the camera is zoomed in.
In addition, many camera applications or systems do not have a user to assist in this corrective repositioning. This can be a very serious problem for an automatic camera tracking system using a PTZ (pan, tilt and zoom) camera, such as in surveillance systems. Maintaining the object of interest in the field of view of the camera during zooming can be critical in such systems.
Accordingly, there has been a long felt need for a method and system to keep the object of interest centered when the camera is optically zoomed in on the object of interest.